| 313 / | HD | ELECTRIC LAMP AND DISCHARGE DEVICES |
| 567 | DF | WITH GAS OR VAPOR {24} |
| 581 | DF | .~ Three or more electrode discharge device {9} |
| 595 | ![]() | .~.~ Internal start or control electrode between discharge electrodes {3} |
| 596 | DF | .~.~.~> Strip electrode |
| 597 | DF | .~.~.~> Interposed apertured electrode {2} |
| 600 | DF | .~.~.~> Two interposed electrodes |